BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

the integer K?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

the integer K?

by sanju09 » Thu Sep 16, 2010 10:19 pm
What is the value of the integer K?

[1] K is a prime number between 40 and 50.

[2] The integer (K + 1) is divisible by exactly two different prime numbers.


[spoiler]Source: https://www.west.net/~stewart/gmat[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Data Sufficiency |
User avatar
Senior | Next Rank: 100 Posts
Posts: 82
Joined: Sat Aug 21, 2010 8:18 am
Location: India
Thanked: 5 times

by sumit.sinha » Sat Sep 18, 2010 5:36 am
sanju09 wrote:What is the value of the integer K?

[1] K is a prime number between 40 and 50.

[2] The integer (K + 1) is divisible by exactly two different prime numbers.


[spoiler]Source: https://www.west.net/~stewart/gmat[/spoiler]
(1) K = 41, 43 or 47 NOT SUFFICIENT
(2) K =5 or 9.
Because 5+1 = 6 is divisible by exactly two different prime numbers 2 and 3.
Note: it is given (K + 1) is divisible by exactly two different prime numbers and NOT (K + 1) is ONLY divisible by exactly two different prime numbers. so there maybe other non-prime factors but we are not concerned about them.
and 9 +1 =10 is divisible by exactly two different prime numbers 2 and 5.
NOT SUFFICIENT

(1) ans (2) together - K = 43 or 47
Because if K = 41, K +1 = 42 is divisible by three different prime factors 2,3 and 7
if K = 43, K +1 = 44 is divisible by exactly two different prime factors 2 and 11
if K = 47, K +1 = 48 is divisible by exactly two different prime factors 2 and 3
NOT SUFFICIENT

CORRECT ANSWER (E)
Cheers,
Sumit
Top
Senior | Next Rank: 100 Posts
Posts: 87
Joined: Wed Jun 16, 2010 7:57 pm
Location: Delhi,India
Thanked: 1 times

by puneetdua » Sat Sep 18, 2010 8:46 am
Should be E.
Thanks
Puneet
Top
Post new topic Post Reply
• Page 1 of 1